The present invention relates to an apparatus for splitting a stream of pulverulent material into a multiplicity of equal streams for pneumatically transporting from a single source to multiple receiving stations.
Flow splitters for dividing a stream of pulverulent material such as pulverized coal entrained in air into a multiplicity of streams are not unknown in the art. A common type of such a device utilizes a conical body disposed in the flow path of the single stream to perfect the division of the stream into a multiplicity of streams. A typical embodiment of such a flow splitter, as disclosed in U.S. Pat. No. 1,769,763, comprises a generally elongated, up-right distributor housing having an inlet in the top and a multiplicity of outlets disposed around its bottom periphery. A conical body is disposed within the housing with the base of the cone at the outlet end of the housing and the apex of the cone pointed upward toward the top of the housing. The conical body may be stationary or it may be rotatable as disclosed in U.S. Pat. No. 1,871,853.
In operation, the pulverulent material is mixed with a transport medium, most commonly air, and passed into the flow splitter in a whirling pattern under pressure supplied by a fan or a compressor. As the stream passes through the distributor housing of the splitter, it diverges outwardly in a swirling pattern over the surface of the conical body and through the various outlets disposed around the face of the conical body into the individual transport lines connected to the opposite end of the distributor housing.
A problem typically encountered with such flow splitters as described above occurs when flow through one or more of the transport lines being fed by the distributor is shut off. Typically a damper or a valve disposed in the transport downstream of the flow splitter is closed in order to shut off flow to the transport line. When the damper or valve is closed pulverulent material can collect and become packed in the transport line between the closed damper or valve and the outlet of the flow splitter to which the line is connected. This blockage of material can cause problems in bringing a transport line back into service as the pulverulent material can become packed to a very high density and act as a block to flow.
Additionally, significant turbulence is generated within the distributor housing in the vicinity of the outlet which opens into the closed line because of surface irregularities presented at the outlets opening in the periphial wall or floor of the distributor housing. As a consequence to this turbulence, the swirling flow pattern within the housing is disturbed and uniform distribution of the pulverulent material amongst the transport lines remaining open is destroyed.
It is therefore an object of the present invention to provide an improved apparatus for splitting a stream of pulverulent material into a multiplicity of streams wherein the packing of transport lines and the disturbance of uniform distribution do not occur when one or more of the transport lines connected to the flow splitter is shut off.